PMID- 33356255
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20210114
LR  - 20220217
IS  - 1520-5215 (Electronic)
IS  - 1089-5639 (Print)
IS  - 1089-5639 (Linking)
VI  - 125
IP  - 1
DP  - 2021 Jan 14
TI  - On the Accuracy of the Direct Method to Calculate pK(a) from Electronic Structure 
      Calculations.
PG  - 65-73
LID - 10.1021/acs.jpca.0c08283 [doi]
AB  - The direct method (HA((soln)) right harpoon over left harpoon A((soln))(-) + H((soln))(+)) for calculating 
      pK(a) of monoprotic acids is as efficient as thermodynamic cycles. A selective 
      adjustment of proton free energy in solution was used with experimental pK(a) 
      data. The procedure was analyzed at different levels of theory. The solvent was 
      described by the solvation model density (SMD) model, including or not explicit 
      water molecules, and three training sets were tested. The best performance under 
      any condition was obtained by the G4CEP method with a mean absolute error close 
      to 0.5 units of pK(a) and an uncertainty around +/-1 unit of pK(a) for any training 
      set including or excluding explicit solvent molecules. PM6 and AM1 performed very 
      well with average absolute errors below 0.75 units of pK(a) but with 
      uncertainties up to +/-2 units of pK(a), using only the SMD solvent model. Density 
      functional theory (DFT) results were highly dependent on the basis functions and 
      explicit water molecules. The best performance was observed for the local spin 
      density approximation (LSDA) functional in almost all calculations and under 
      certain conditions, as high as those obtained by G4CEP. Basis set complexity and 
      explicit solvent molecules were important factors to control DFT calculations. 
      The training set molecules should consider the diversity of compounds.
FAU - Dutra, Felipe Ribeiro
AU  - Dutra FR
AD  - Instituto de Quimica, Universidade Estadual de Campinas, P.O. Box 6154, Barao 
      Geraldo, 13083-970 Campinas, Sao Paulo, Brazil.
FAU - Silva, Cleuton de Souza
AU  - Silva CS
AD  - Instituto de Ciencias Exatas e Tecnologia, Universidade Federal do Amazonas, 
      Campus de Itacoatiara, 69100-021 Itacoatiara, Amazonas, Brazil.
FAU - Custodio, Rogerio
AU  - Custodio R
AUID- ORCID: 0000-0002-1824-2521
AD  - Instituto de Quimica, Universidade Estadual de Campinas, P.O. Box 6154, Barao 
      Geraldo, 13083-970 Campinas, Sao Paulo, Brazil.
LA  - eng
PT  - Journal Article
DEP - 20201224
PL  - United States
TA  - J Phys Chem A
JT  - The journal of physical chemistry. A
JID - 9890903
SB  - IM
CIN - J Phys Chem A. 2022 Feb 3;126(4):648-649. PMID: 35051330
PMC - PMC7872415
COIS- The authors declare no competing financial interest.
EDAT- 2020/12/29 06:00
MHDA- 2020/12/29 06:01
PMCR- 2021/02/09
CRDT- 2020/12/28 10:06
PHST- 2020/12/29 06:00 [pubmed]
PHST- 2020/12/29 06:01 [medline]
PHST- 2020/12/28 10:06 [entrez]
PHST- 2021/02/09 00:00 [pmc-release]
AID - 10.1021/acs.jpca.0c08283 [doi]
PST - ppublish
SO  - J Phys Chem A. 2021 Jan 14;125(1):65-73. doi: 10.1021/acs.jpca.0c08283. Epub 2020 
      Dec 24.